• Korean Journal of Organic Agriculture
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• v.20 no.3
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• pp.369-383
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• 2012

This experiment was carried out to investigate the optimal stocking rate of earthworm populations grown under different stocking rates. The stocking rate in terms of ratio of biomass of earthworms to biomass of feeds(organic resources) is an important factors for biomass productivity of earthworms and vermicast production. The different stocking rates were 1:16(S-1), 1:32(S-2), 1:48(S-3) and 1:64(S-4), as the ratios of biomass of earthworm to biomass of organic dairy cow manure, respectively. The stocking rate of 1:32(S-2) and 1:46(S-3) were obtained a higher values on increasing rates and conversion efficiency of organic matter to earthworm biomass than other stocking rates. Thus, a stocking rates of 1:32 and 1:46 estimated an optimal stocking rates for maximum biomass productivity of earthworms. A stocking rate of 1:16(S-1) showed a significantly highest values of vermicast production and ratios of vermicasts during the rearing periods.($$P{\leq_-}0.05$$) A stocking rate of 1:48(S-3) showed a highest values of the number of cocoons and vermicasts production per earthworm biomass among the treatment ($$P{\leq_-}0.05$$) The contents of nitrogen, available phosphorus, cation exchange capacity and exchangeable cations of vermicasts tended to increase with stocking rate and rearing progressed. Vermicasts have a great deal of potential for crop production and protection in sustainable organic cropping systems.

• Journal of Animal Environmental Science
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• v.18 no.2
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• pp.63-74
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• 2012

This experiment was carried out to investigate the effect of different stocking rate on growth, cast production and conversion efficiency of organic matter to tissues of earthworm. The carbon and nitrogen ratio (C/N) of tested Korean cow manure was 25.1, it was estimated an adequate ratio as feed for earthworms. The different stocking rates were 1:8(S-1), 1:16(S-2), 1:32(S-3) 1:64(S-4) 1:128(S-5) and 1:256 (S-6) as the ratios of earthworm fresh weight to biomass of Korean cow manure, respectively. A stocking rate of 1:32(S-3) was obtained a significantly highest values of increasing rate and conversion efficiency of organic matter to earthworm tissues. The mean values of increasin g rate of fresh weight and conversion efficiency of organic matter to earthworm tissues were 10.63 mg/day and 6.65% at the ratio of 1:32(S-3) with a rearing volume was $56.6cm^3$. A stocking rate of 1:8(S-1) was obtained a highest ratio of vermicasts, but showed a negative values of increasing rate and conversion efficiency of organic matter to earthworm tissues, it may due to severely food competition between individuals during the rearing periods. The pH, total nitrogen, available phosphorus, cation exchange capacity and exchangeable cations of vermicasts tended to increase with stocking rate. Especially, available phosphorus, cation exchange capacity and exchangeable cations of vermicasts tended to increase with rearing progressed. Vermicasts have the potential for improving plant growth when amended to container medium and soil according to increased availability of nutrients and improved physicochemical properties.

• Journal of the Korea Organic Resources Recycling Association
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• v.21 no.2
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• pp.79-87
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• 2013

Effects of pig manure with various composting periods(0, 15, 30, 50, 80 days) on feeding rate, biomass, cocoon production of earthworm(Eisenia fetida) population and physicochemical property of vermicast produced from pig manure were investigated. The feeding rate of earthworm was increased with longer composting period of pig manure. But the biomass production of earthworm population was highest upon the pig manure composted for 30 days. Upon the pig manure composted for 80 days, the biomass was severely reduced. Cocoon production was decreased with longer composting period and especially lower on the pig manure composted for 80 days. Values of pH, EC, C/N ratio of vermicasts produced from pig manure composts were lower than those of pig manures. And the organic material contents of vermicasts were uniformly reduced irrespective of composting duration of pig manure, whose values were 35.9-39.8%. From these results, the optimum composting period of pig manure for vermicomposting could be 15-30 days. And the application of vermicomposting upon the composted pig manure could be an efficient way for the treatment of pig feces, which can stabilize and recycle the organic wastes more rapidly than the conventional composting method.

• Korean Journal of Organic Agriculture
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• v.16 no.3
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• pp.299-308
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• 2008

In this study, the effect of commercial organic growth medium amended with different ratios of vermicast on the growth of rice seedlings. The amended ratios of vermicast were 0% (control), 5%, 10%, 20% and 40%, respectively. A bioassay with two rice varieties (Chucheng and Black) was conducted to assesses the amendment effect of vermicast on the seedling growth in two potting methods. In potting treatment, the Chucheng variety with late maturity showed significantly higher values on growth parameters excepted root weight (RW) up to 20% and Black variety with early maturity up to 10% amended with vermicast, respectively. In floor layering treatment, all of the growth parameters significantly increased up to 5% amended with vermicast in both rice variety. The seedling growth of rice in floor layering treatment attained the highest values at lower amended ratios of vermicast than those of potting treated only, it may correspond with increased uptake of nutrient by elongated root grown under the layering amendment of vermicast. Vermicasts can be used as soil amendments or components of plant growth medium for seeding organic agriculture.

• Journal of the Korea Organic Resources Recycling Association
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• v.18 no.4
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• pp.45-53
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• 2010

Feeding rate and growth rate of earthworm population on the variously pretreated spent materials of the agaric-mushroom cultivation were investigated. When the spent mushroom substrates with different aging periods were supplied to earthworm, feeding rate and growth rate of earthworm population on spent mushroom substrates aged less than 10 days were higher than that on spent mushroom substrates aged more than 20 days. Feeding rate and growth rate were not increased when the spent mushroom substrate mixed with vermicasts or nitrogenous fertilizer was supplied. Feeding rate and growth rate on the ground mushroom substrate were higher than that on the non-ground mushroom substrate. Especially when the ground mushroom substrate was mixed with rice bran and supplied to earthworms, growth rate was much higher than that on the non-ground spent mushroom substrate; it increased 1.85 times.

• Korean Journal of Organic Agriculture
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• v.13 no.4
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• pp.413-422
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• 2005

This study was carried out to investigate the effect of different mixture ratios of vermicasts on the growth of leaf beet(Beta vulgaris var. cicla), young radish (Raphanus sativus L), spinach(Spinacia oleracea) and lettuce(Lactuca sativa) The mixture of ratios of vermicast(fermented pig manure with sawdust) and peatmoss were 100%+0%, 60%+40%, 40%+60% and 0%+100%(control), respectively. The bulk density, particle density, pH, electrolytic conductivity, ash, total nitrogen, cation exchange capacity, available phosphorous and exchangeable cations increased significantly compared to those grown in the 100% of peatmoss(control). The significantly higher values of plant length, leaf area, shoot dry weight, root weight, root length and biological yield obtained were $40{\sim}100%$ and 40% of vermicast in leaf beet and lettuce, respectively. The young radish and spinach showed that significantly differences of shoot dry weight, root weight and biological yield in the mixture ratios of vermicast were $40{\sim}60%$ and 40% in young radish and spinach, respectively.